Method and apparatus for hot galvanizing iron or steel articles



Sept. 21, 1937. H. v. WILLIAMSON ET AL 2,093,357

METHOD AND APPARATUS FOR HOT GALVANIZING IRON OR STEEL ARTICLES FiledOct. 4, 1954 2 Sheets-Sheet l In H IEIVEEIEE Sept. 21, 1937. H. v.WILLIAMSON ET AL 2,093,857

METHOD AND APPARATUS FOR HOT GALVANIZING IRON OR STEEL ARTICLES FiledOct. 4. 1954 2 Sheets-SheetZ IN; v E323 car-1 Patented Sept. 23., 13.93?

METHOD AND APPARATUS FOR HOT GAL- VANIZING IRON OR STEEL ARTICLES HugoV.Williamson, Pekin, and Andrew 0. Simmons, Peoria, 111., assignors toKeystone Steel 7 Illinois & Wire Company, Peoria, 111., a corporation ofApplication October 4, 1934, Serial No. 746,822

14 Claims.

This invention has reference to a. new and improved method of hotgalvanizing iron or steel articles and of quenching or chilling thecoating and article with water before permitting the coated article tocome in contact with the atmosphere and therebyprevent even the normaloxidation which ordinarily occurs at the finish of the usual steps ofzinc coating; and to an. apparatus for employing the method.

The invention has for its principal object to 1 zinc coat iron or steelarticles by the hot galvanizing method whereby to produce a silverbright article, as distinguished from the usual bluish tint zinc coatedarticle. Such a zinc coating has its appeal, from a sales standpoint inregard to attractive luster or finish, especially when the articlecoated is wire, and where the coating is smooth and of very lightweight. By our method we produce a coated wire having thesecharacteristics and such as will permit of severe forming withoutappreciable cracking or peeling of the coating and the subsequentabrasion of the forming dies of various machines is considerably reducedby the use of a smooth,

. bright finish. Coated wire so produced finds its greatest use in pailbale handles; coat hangers; hooks, etc., wire baskets, crates, and tyingwires of all descriptions.

Further objects of the invention will more fully appear from thefollowing description taken in connection with the accompanyingdrawings, illustrating a preferred embodiment of the invention, inwhich:

Fig. 1 is a more or less diagrammatic, longitudinal sectional viewthrough a hot galvanizing apparatus for zinc coated wire and with myimprovements associated therewith for wiping and quenching or chillingthe coated wire by means of water;

Fig. 2 is a perspective view of a unit assembly embodying wipingelements and means of water application for producing a silver brighluster or finish to the zinc coating;

Fig. 3 is a transverse sectional detail through the unitassembly showingthe wiper and water applying means, and

Fig. 4 is a sectional detail of an adjustable nozzle for supplying acold stream of water to the bath and coated wire, immediately as thewire leaves the wines.

Like characters of reference denote corre- .sponding parts throughoutthe figures.

. While our method and apparatus may have general application to the.hot galvanizing of zinc coated iron or steel articles, we prefer in'(CH. Ell-12.5)

In Fig. 1 an outline of a typical zinc furnace l is shown, in which isremovably supported a Zinc pan 2 containing molten zinc 3; The wire tobe coated is directed to the pan over a guide oizroller l, thence undera sinker 5 within the pan and thence over a roller 6, after the coatedwire leaves the pan, It is at the exit end of the pan that we locate theunit assembly embodying the wipes and the water quenching or chillingmeans, as shown in Fig. 1 and detailed in Figs. 2 and 3. 1

While the present invention does not involve the usual and customarysteps of annealing, pickling, fiuxing and drying the wire beforesubjecting the wire to the hot galvanizing bath, these steps are ofcourse factors which are here recognized because time and temperatureplay their part, depending on the gauge or size of wires to be coated.The larger the wire, the longer immerslon in the zinc bath, keeping thespeed constant. In practice, due to the fact that the zinc bath hascertain physical limitations, it is sometimes necessary to reduce therate of travel of the wires in order to permit the wires to remain inthe bath for the necessary length of time. In some cases, particularlywhere elongation requirements area factor, it is necessary to operate atslower speeds with certain heats of steel which are not extremelyductile.

The unit assembly, embodying the wipes and the water applying means, towhich reference has been made, is best seen in perspective in Fig. 2 andin section in Fig. 3. This unit comprises a base member I with extensiontrunnions 8 from its opposite ends and said trunnions are manuallyrockable in split bearings 9 provided with nuts and bolts for securelyholding the.

trunnions firmly in adjusted positions. The low er half of each of thesesplit bearings is secured to preferably angle irons secured to theoutside of the side walls of the pan 2., Extending the length of thebase, between the trunnions, and disposed forwardly thereof for asuitable distance,

is a trough 10 which is divided into a multiplicity I of watercompartments H by a multiplicity of transversely arranged partitions l2,the upper overflow notch l4, preferably centrally disposed, with thebase of the V shaped notch being lo-' cated above the bottom of thetrough, a suitable distance. The upper face of the base 1 is preferablyinclined forwardly and upwardly from its rear edge, see Fig. 3, whereasthe bottom of the trough I0 is substantially horizontal or fiat and thefront wall l3 and partitions l2 are disposed vertically and at rightangles thereto. Ex-

tending upwardly from the base 1, at each end of the trough l0, anddisposed at right angles to the upper surface of the base, are supports!5 connected at their upper ends by a cross-frame l6. Extendinglengthwise of the base 1, between the supports l5, are a pair of spacedbars l1 and IS, the lower face of the former being preferably above therearwardly inclined upper edge of the partitions l2, while the bar I8 isspaced a suitable distance above the bar I'l. Threaded through thecross-frame l5 and the bars I! and I8 are compression screws [9 havingtheir upper ends squared, as at 20, to be engaged by a suitable tool forthreading the screws downwardly or .for retracting the same, in mannerwell understood where compression wipes are used. In this connectionthere is a screw l9 coincident with each water compartment H, and thelower end of each screw where it protrudes through the lower bar I! isconnected with a pressure plate 2i, and in such a manner that the platemay be lowered and raised bodily while at the same time the screw isactuated. Between each pressure plate 2| and the upper surface of thebase l are arranged a series of asbestos wipes 22.

The unit assembly, as now described, is so placed and disposed that acoated wire A leaving the zinc bath travels in substantially a straightline, inclined upwardly, from the sinker 5 in the'pan 2 to and over theroller 6 and between asbestos wipes 22 and through a water compartment Hin the trough I0, as is seen in Fig. 3. The combination of elements thusfar described constitutes the wipe portion of 'the assembly, even thoughthe water containing trough I0 is included. The trunnions 8 permittilting of the wiping part of the apparatus and the trough H1, in orderto obtain the best water application in conjunction with the position ofthe coated wires being treated. In practice, it is desirable, and infact necessary, for the wipes (that is the asbestos parts of the wipes)and the compression screws to be perpendicular to the travel of thecoated wires. wires from cutting in either the bottom part of theasbestos wipe or the upper section. The positions of the wires are moreor less determined by the installation of the pan 2 and the roller 6.While this adjustment, in practice, is

made only when a new pan 2 is installed, or when extra large wires arebeing galvanized, nevertheless the simple means of obtaining thisadjustment, by means of the trunnions 8, on the ends of the wipe, is avaluable adjunct to the wiping, because it eliminates the formerpractice of obtaining this adjustment (that is perpendicular to thetravel of the wire) by means of wedges and shims.

The angle at which the coated wires travel, as they leave the bath, andthe consequent adjustment of the trunnions 8 will control the height ofthe water in the trough H), see Fig. 3. As will be readily understood,it will be desirable, at times, to use two or more top asbestos wipes 22in order to have the wires, in their travel, submerged under the maximumamount of water.

This will prevent thev In no case should the water in the trough bepermitted to flow over the top of the wipes 22 and in this way enter thepan 2, because if it does it will freeze the zinc back of the wipes andcause the wires to break. The angle of travel of the wire from the zincbath is contingent somewhat upon the position of the roller 6 and itslocation in reference to the sinker 5. To obtain the best results, theangle of withdrawing the wire from the zinc bath should be as acute asthe apparatus will permit.

Water is furnished and applied to the coated wires immediately on theiremerging from the wipes 22 in the following preferred manner. 23designates a reservoir which is at least as long as the trough I0 andadjustably supported thereabove. The sides of the reservoir preferablyconverge inwardly and downwardly and coupled to the bottom of thereservoir and depending therefrom are a plurality of discharge pipes 24,one above each compartment II in the trough I0. Adjustably connected tothe lower end of each pipe 24 is a discharge nozzle 25, see Figs. 3 and4, which depend to a convenient point for discharge of water into thecompartments H of the trough l0 and onto the coated wires travellingthrough the water in said trough. The connection of each nozzle 25 witha pipe 24 is concentric so that it may be adjusted about said pipe. Thedischarge end 26 of each nozzle is eccentric to its body which gives awide range of adjustment so that the end of the nozzle may be locatedabove a wire with the travelling wire intersecting the axis of the flowof water from the nozzle.

The reservoir 23 is supported at its opposite ends by stationarysupports 26 from the base I. These supports, at their upper ends, areprovided with vertically arranged slots 21 and extending from each endof the reservoir are threaded members 28 which pass through and have abearing in the slots 21 of the supports 26 to permit of verticaladjustment of the reservoir on its supports and also serve as a fulcrumpoint about which the reservoir and its discharge nozzles may havepivoted adjustment. Locking nuts 29 on the threaded members are employedto secure the reservoir in fixed and adjusted positions. Thus it will beseen that the position of the wipes in relation to the angle of travelof the coated wires and the height of the water in the trough, may bedetermined by adjusting the wipe support and trough on the trunnions 8and the reservoir with its discharge nozzles may be raised and loweredas well as pivoted on the members 28 and the nozzles adjusted, so that aproper direction of flow of water on the wires may be obtained.

The reservoir 23 is provided with an overflow pipe 30, and means areprovided to shut off the water outlets from the reservoir to thedischarge pipes 24. These means comprise a plurality of verticallyadjustable plugs 3| having tapered lower ends serving as closing valveswhen caused to enter the inlet ends of the pipes 24 and said plugs havea sliding and frictional fit within sleeves 32 supported in dependingpositions within a frame 33 disposed longitudinally in the upper part ofthe reservoir. Water may be supplied to the reservoir through a feedpipe 34 from any suitable source, and the volume required adjusted andmaintained by a suitable valve, not shown, because in practice it isoften desirable that the height ofwater, which determines its pressure,be considerably less than that which is wardly and downwardly from thetrough l and has preferably side walls converging to its discharge end.The slot in the pipe 36 will permit of such adjustments as may be madein the Wipe support.

In operation, the coated wires leave the zinc vbath at approximately 900F. and immediately enter between the asbestos wipes and on leaving thewipes pass through water in the trough the level of the water beingabove the wires at the point of exit of the wire'sfrom the wipes, and byemploying a steady stream of water without a great deal of force on thewires, by the use of the reservoir and nozzles, no air bubblesarepermitted to form along the wire and the dull gray spots are reduced. Byimmersing the coated wires, as they leave the wipes, in water andconstantly applying a cold stream thereon, we are able to quench orchill the coating of zinc to the point where oxidation does not occur,yet the heat of the wire is sufficient to dry any adhering water whichremains on the surface.

Water quenching or cooling per se is not broadly new but so far as weare aware such applications are and have been made after the wire hascome into contact with the atmosphere. By our method and apparatus thecoated wire does not come into contact with the atmosphere until afterthe water treatment. The preferred speed of travel of the wire is thatspeed which will permit obtaining the correct physical properties, auniform coating free from any defects caused by excessive vibration orpinching ofi due to freezing of the Dillberry (an expression whichdescribes an envelope or accumulation of surplus zinc and skimmingswhich collects around the coated wires back of the wipes and between thewipes and the surface of the molten zinc), and at a speed which permitsthe water to sufiiciently quench or chill the wire so that when itleaves the Water in the trough I0 it is cooled to a point whereoxidation, if any, is reduced to a minimum. The coating obtained by thismethod of galvanizing is extremely smooth, light in weight and permitssevere fabrication. The gauge or size and roundness' of the wire may beheld within very close limits due to the thinness of the coating plusits uniformity. The smoothness of the coating obtained lends itself tomany operations. The attractiveness of the silver bright" finish makesthe wire very desirable for articles which are not subjected to severeexposure, and the brightness is a sales point for many of the articlesmanufactured from such wire. The resulting coating obtained while onlymoderately protective, nevertheless is ample for many uses to which thiswire is put. It also is of such a thin nature that permits the weldingof this product without excessive obnoxious fumes during he weldingoperation.

While the coated wire enters the trough ID at a temperature in theneighborhood of 900 the water in the trough is continuously being.replenished from the reservoir 23 through the nozzles 25. Change ofdegree in volume of water may be obtained by changes in sizes of nozzlesand the depth of water in the reservoir 23, but the practicallimitations here are quite narrowly refront wall of the trough and thefact that the streams of water from the reservoir must not splashexcessively. It is obvious, therefore, that with a large size wire it isnecessary to operate at a slower speed than with the smaller gauges, inorder to obtain the quenching or chilling efiect necessary beforepermitting the wire to contact the atmosphere. Practice has shown thatit is not possible to operate by our method at too slow a speed due tothefact that the zinc which is removed by the wipes and forming aDillberry backof the wipes may become solidified or frozen to such anextent that it pinches off the fine wires. This defect we have noticedwhen coating a #14 gauge wire at a speed of less than 80 ft. per minute.It is also noticeable on the heavier gauges of wire when operating atless than 70 ft.

per minute, by a decided chattering or vibration,

which in turn causes a roughness of the coating.

In practice, it is desirable that the discharge of the water from thetrough I 0 be approximately equal to that which is supplied from thereservoir through the nozzles 25, so that the trough to may always befilled with water. The constant pressure of water and volume iscontrolled by means of the reservoir and its overflow. The reservoirwill provide an ample volume of water, yet a lazy stream in order tominimize the bubbles which would form if a rapid stream of water wasinjected into the trough. By the use of the shut ofi plugs 31 the flowof water to any of the compartments It in the trough l0 may be cut ofi.By means of the overflow any non-uniformity in the supply of water tothe reservoir may be taken care of.

By adjustably supporting the reservoir the discharge of the water fromthe nozzles may be controlled so that the water may be dischargeddirectly over the wires and at a point between the asbestos wipes andthe point where the wires emerge from the trough I0. This adjustablefeature is necessary when the wipes proper are tilted because it permitsof leveling up the reservoir 50 that the streams of water will not hitthe wires after they have left the trough l0. Furthermore, it will benoted that the V shaped notches providing for the overflow from thetrough I'll, are

ample to take care of the condition when it is any or all of thecompartments llv of the trough Ill, to a point .where the water in thetrough is below the bottom wipe, so that when these wipes are changed nowater will flow back into the zinc bath proper.

What we claim is:-

1. The method of zinc coating iron or steel articles to produce a silverbright luster or finish to the coating. which consists in subjecting thearticle to a molten zinc bath; passing the coated article betweencompression wipes immediately on removal of the same from the bath priorto substantial atmospheric exposure. and quench ng or chilling the zinccoating as the coated a"*icle leaves the wipes and before the coated aticle comes in contact with the atmosphere by immediately introducingthe coated the article to a molten zinc bath; passing the coated articlebetween compression wipes immediately on removal of the same from thebath before substantial exposure to the atmosphere, and quenching orchilling the zinc coating as the article leaves the Wipes and beforeexposure to atmosphere by immediately introducing the coated articleinto a water bath at a point below the surface thereof and maintaining aproper temperature of the water bath by constantly applying a coldstream of water thereto.

3. The method of zinc coating an iron or steel wire to produce a silverbright luster or finish to the coating, which consists in passing thewire through a molten zinc bath, wiping the coating and immediatelyintroducing the coated wire into water bath and at a point below thesurface thereof before the coated article comes in contact with theatmosphere, whereby to quench and chill the coating and thereby preventoxidation.

4. In an apparatus of the character described,- in combination with amolten zinc bath, a unit including compression wipes and a water bathsupported at the exit end of the zinc bath whereby the zinc coated wiresenter between the wipes immediately on leaving the zinc bath withoutsubstantial atmospheric exposure and on leaving the wipes areimmediately submerged within and passed through the water in the waterbath before the coated wires come in contact with the atmosphere, andmeans for supplying a cold stream of water to the surface of the waterbath.

5. In an apparatus of the character described, in combination with amolten zinc bath, a unit including compression wipes and a water bathsupported at the exit end of the zinc bath whereby the zinc coated wiresenter between the wipes before substantial exposure to the atmosphereand immediately on leaving the zinc bath and are directly introducedinto and pass through the water bath immediately on leaving the wipesand before the coated wires come in contact with the atmosphere, meansfor supplying a cold stream of water to the surface of the water bath,means for adjusting the position of the wipes in relation to the planeof travel of the wires from the zinc bath, and means for adjusting thewater supply to the water bath.

6. In an apparatus of the character described, in combination with amolten zinc bath, a unit comprising compression wipes, a water troughand reservoir supported at the exit end of the zinc bath whereby thezinc coated wires enter between the wipes immediately on leaving thezinc bath and prior to atmospheric exposure and are directly introducedinto and pass through water in the trough immediately on leaving thewipes and before the coated wires come in contact with the atmosphere,means for supplying water from the reservoir to the trough, means foradjusting the position of the wipes in relation'to the plane of travelof the wires from the zinc bath, and means for adjustably supporting thereservoir and for regulating the point of discharge of water into thetrough.

'7. In an apparatus of the character described, in combination with amolten zin'c bath, a unit comprising compression wipes, a water troughand reservoir supported at the exit end of the zinc bath whereby thezinc coated wires before substantial atmospheric exposure enter betweenthe wipes immediately on leaving the zinc bath and are directlysubmerged within and pass through water in the trough immediately onleaving the wipes and before the coated wires come in contact with theatmosphere, a plurality of adjustable discharge outlets for water fromthe reservoir to the trough, means for regulating the flow of water fromthe reservoir through said discharge outlets, an overflow from saidreservoir, a source of water supply to said reservoir, means foradjusting the position of the wipes in relation to the plane of travelof the wires from the zinc bath, and means for adjustably supporting thereservoir and said discharge outlets.

8. In an apparatus of the character described, in combination with azinc bath, a unit comprising a series of compression wipes, one set foreach wire, a water trough in advance of the wipes and a reservoir abovethe trough arranged so that the coated wires prior to substantialatmospheric exposure enter between the wipes immediately on leaving thezinc bath and are immersed in and pass through water in the troughimmediately on leaving the wipes and before the coated wires come incontact with the atmosphere, said trough divided into a series ofseparate water compartments, one for each wire, and having an overflow,a discharge pan to receive water overflowing from said trough, means toconvey waste water from said pan, a plurality of discharge outlets fromthe reservoir for supplying streams of water to the trough, one aboveeach compartment, means for adjusting the position of the wipes inrelation to the plane of travel of the wires from the zinc bath, andmeans for adjustably supporting the reservoir.

9. In an apparatus of the character described, in combination with azinc bath, a unit comprising a series of compression wipes, one set foreach wire, a water trough in advance of the wipes and a reservoir abovethe trough arranged so that the coated wires prior to substantialatmospheric exposure enter between the wipes immediately on leaving thezinc bath and are immersed in and pass through water in the troughimmediately on leaving the wipes and before the coated wires come incontact with the atmosphere, said trough divided into a series ofseparate water compartments, one for each wire, and having an overflow,a discharge pan to receive water overflowing from said trough, means toconvey waste water from said pan, a plurality of discharge nozzlesdepending from said reservoir, one above each compartment, andadjustable eccentrically whereby to be positioned for discharging astream of water into said trough above a coated wire, means to controlthe flow of water from the reservoir to the discharge nozzle, means foradjusting the position of the wipes in relation to the plane of travelof the wires from the zinc bath, and means for adjustably supporting thereservoir.

10. In an apparatus of the character described, in combination with amolten zinc bath, a unit comprising compression wipes, a water troughand reservoir arranged so that the coated wires prior to substantialexposure to the atmosphere enter between the wipes immediately onleaving the zinc bath and are immersed in and pass through water in thetrough immediately on leaving the wipes and before the coated wires comein contact with the atmosphere, means for pivotally supporting the unitin respect of the zinc bath, means for vertically and pivotallyadjusting the reservoir in its relation to the trough, adjustable wateroutlets for regulating the discharge of water from the reservoir to thetrough, means to carry off waste water from the trough,

and means to supply the reservoir with wate from a source of supply.

11. In an apparatus of the character described, in combination with amolten zinc bath, a unit including wipes and a water bath supported atthe exit end of the zinc bath, the inlet end of the wipes being in closeproximity to the level of the zinc bath and the outlet end of the wipesbeing submerged below the level of the water bath. whereby the coatedarticle is not substantially exposed to atmosphere until after its exitfrom the water bath.

12. In an apparatus of the character described, in combination with amolten zinc bath, a unit including wipes and a water bath supported atthe exit end of the zinc bath, the inlet end of the wipes being in closeproximity to the level of the zinc bath and the outlet end of the wipesbeing submerged below the level of the water bath, whereby the coatedarticle is not substantially exposed to atmosphere until after its exitfrom the water bath, and means for pivotally adjusting the unit tocontrol the level of water in the water bath.

13. In an apparatus of the character described, in combination with amolten 'zinc bath, a unit including wipes and a water trough supportedat the exit end of the zinc bath, means for supplying a liquid to thewater trough, one end of the wipes forming one of the walls of the watertrough, the inlet end of the wipes being in close proximity to the levelof the zinc bath and the outlet end of the wipes being below the levelof the liquid in the water trough whereby the coated article is notsubstantially exposed to atmosphere until after its passage through theliquid in the water trough.

14. In an apparatus of the character described, in combination with amolten zinc bath, a unit including wipes, a water trough, a reservo andducts leading from the reservoir to the water trough, one end of thewipes forming one of the walls of the water trough, the inlet of thewipes 'being in close proximity to the level of the zinc bath and theoutlet of the wipes being below the 7 level of the liquid in the watertrough whereby the coated article is not substantially exposed toatmosphere until after its passage through the liquid in the watertrough.

HUGO V. WILLIAMSON. ANDREW C. SIMMONS.

